• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 829
  • 313
  • 142
  • 97
  • 91
  • 36
  • 29
  • 20
  • 14
  • 14
  • 7
  • 7
  • 6
  • 5
  • 5
  • Tagged with
  • 1882
  • 218
  • 175
  • 160
  • 160
  • 151
  • 117
  • 116
  • 96
  • 95
  • 94
  • 91
  • 90
  • 89
  • 86
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
741

Novel Techniques For Selective Doping Of Silicon Carbide For Device Applications

Krishnan, Bharat 11 December 2009 (has links)
Superior properties of Silicon Carbide (SiC), such as wide bandgap, high breakdown field and high thermal conductivity, have made it the frontrunner to replace Silicon for applications requiring high breakdown strength, mechanical and radiation hardness. Commercial SiC devices are already available, although their expected performance has not yet been realized due to a few problems related to device fabrication technologies, such as selective doping. This work explores non-traditional techniques for SiC doping (and selective doping in particular) based on previously unknown types of defect reactions in SiC and novel epitaxial growth techniques, which offer advantages over currently available technologies. Recent developments in SiC epitaxial growth techniques at MSU have enabled the growth of high quality SiC epitaxial layers at record low temperatures of 1,300°C. Lower growth temperatures have enabled highly doped epilayers for device applications. Prototypes of SiC PiN diodes fabricated, demonstrated low values of the series resistance associated with anodes grown by the low temperature epitaxial growth technique. At room temperature, 100 ìm-diameter diodes with a forward voltage of 3.75 V and 3.23V at 1,000 A/cm2 before and after annealing were achieved. The reverse breakdown voltage was more than 680 V on average, even without surface passivation or edge termination. Reduced growth temperatures also enabled the possibility of selective epitaxial growth (SEG) of SiC with traditional masks used in the SEG in Si technology. Previously, SEG of SiC was impossible without high temperature masks. Good quality, defect free, selectively grown 4H-SiC epilayers were obtained using SiO2 mask. Nitrogen doped selectively grown epilayers were also obtained, which were almost completely ohmic, indicating doping exceeding 1x1019 cm-3. Moreover, conductivity modulation via defect reactions in SiC has been reported as a part of this work for the first time. The approach is based on a new phenomenon in SiC, named Recombination Induced Passivation (RIP), which was observed when hydrogenated SiC epilayers were subjected to above bandgap optical excitation. Additional acceptor passivation, and thereby modification of the conductivity of the epilayer, was observed. Results of investigations of the RIP process are presented, and conductivity modulation techniques based on the RIP process are proposed.
742

Fear and Assessment of Safety in Rats Selectively Bred for Differential Emission of 50 kHz Ultrasonic Vocalizations

Webber, Emily Sophia 12 August 2009 (has links)
No description available.
743

FASCICULAR PERINEURIUM THICKNESS, SIZE, AND POSITION AFFECT MODEL PREDICTIONS OF NEURAL EXCITATION

Grinberg, Yanina 02 April 2008 (has links)
No description available.
744

Shape Optimization for in Vitro and In Vivo Biomedical Sensing

Nair, Sumitha Parameswaran 31 March 2009 (has links)
No description available.
745

COPPER(I) CATALYZED EXO-SELECTIVE [CN+C+CC] 1,3-DIPOLAR CYCLOADDITIONS and STUDIES TOWARDS THE TOTAL SYNTHESIS OF KAITOCEPHALIN

HU, JIEYU 27 May 2010 (has links)
No description available.
746

Evolution of Epitope regions in HIV genome: Delineating Selective Forces acting on Conformational and Linear Epitopes

Perikala, Satish Kumar 12 April 2010 (has links)
No description available.
747

Gas Adsorption Applications of Porous Metal-Organic Frameworks

Ma, Shengqian 29 April 2008 (has links)
No description available.
748

Total Synthesis of Natural Product Pterocarpans Useful as Selective Estrogen Receptor Modulators

Malik, Neha January 2013 (has links)
No description available.
749

Why Motivations Matter: Information-Processing Goals and Their Implications for Selective Exposure to Political Information

Carnahan, Dustin 21 May 2015 (has links)
No description available.
750

Learning Healthy Sleep Behaviors: The Importance of Selection, Self-Concepts, and Social Comparison in Narrative Self-Education

Robinson, Melissa J. 25 May 2017 (has links)
No description available.

Page generated in 0.0288 seconds